How to pump out black water tank???

[phillyg]

1993 300. Can't seem to get the flow started and I'm wondering if I need to open a valve somewhere to reduce back-pressure. There is a macerator pump on the boat and it appears to to have a "y" valve but I don't know which position to move it to. I just don't know how the system is supposed to work and can't find any literature anywhere online to explain it. Can anyone explain it to me or point me in the right direction?

Thanks, Phil

 

[arks]

Re: How to pump out black water tank???

Yeah, If the Y valve is plumbed between the holding tank and pump-out fitting (which it should), you've got to move it to the pump-out position.
Exactly WHICH position can be determined by process of elimination. You've already tried it once, so THAT position can pretty much be ruled out. Turn it the other way and try it. The system is vented so there should be no other valve to 'reduce back pressure'.

Now, if you try it in every position and it still doesn't pull then you've got a problem. Could be a blocked vent, bad Y valve, or hose that's not able to pull a vacuum due to an air leak.
Hope this helps. Good luck.

 

[phillyg]

Re: How to pump out black water tank???

Thanks Arks, I'll give it a try in the other position next time I visit the boat.